• Korean Journal of Optics and Photonics
• /
• 제5권4호
• /
• pp.439-444
• /
• 1994

When diffraction by arbitrary two-dimensional surface-relief dielectric gratings is analyzed using the rigorous three-dimensional vector coupled-wave analysis, it is found that the matrix eigenvalue problem pertaining to the analysis can always be simplified to that for a matrix which has the dimension of a quarter of the original, so that computing time and memory requirements for computer may be greatly reduced. However this kind of simplification can not be obtained in the case of volume diffraction gratings. tings.

• Journal of the korean Society of Automotive Engineers
• /
• 제6권2호
• /
• pp.1-6
• /
• 1984

복잡한 연소과정의 예측을 위한 이론적인 연구는 Gosman, Spalding, Patankar등의 수치해석방 법을 이용하여 진행된 것들이 많다. 현재 이분야에 응용되는 일반적인 Program으로는 Boundary Layer Type의 방정식을 이용한 One-Dimensional Program (GENMIX 4, Revised GENMIX) 등이 있으나 Parabolic Type이므로 주방향에 수직된 방향으로 동일한 값이 2개 이상 존재할 수 있는 Elliptic현상을 설명하기에는 어려움이 있다. 그러므로 비록 기억용량(Computation Storage) 및 계산시간(Running Time)에 불리한 점이 있기는 하나 Elliptic상황을 해석해야만 할 경우가 있다. 본 해설은 Patankar의 Elliptic "SIMPLE" Program을 연소 해석과정에 이용되는 방법을 간단한 연소과정의 예로서 설명하는 것으로 연소과정의 연구보다도 Program의 응용성에 중점을 두었다. 따라서 실제의 물리적인 연소 mechanism에서 많은 가정을 도입하여 문제를 단순화 시켰으며 실제의 연소문제에 충분한 접근을 위해서는 turbulence-modeling과 radiation heat flux가 본 해설에 덧붙여져서 논의되어야 한다. 논의되어야 한다.

• The Journal of Information Technology and Database
• /
• 제4권2호
• /
• pp.3-19
• /
• 1998

관계형 데이터베이스 성능을 향상시키는데 중요한 요소 중의 하나는 트랜잭션을 처리하기 위해 데이터를 디스크에서 주 기억장치로 옮기는데 필요한 디스크 액세스(access) 횟수이다. 본 연구는 관계형 데이터베이스에서 트랜잭션을 처리할 때, 릴레이션(relation)을 속성의 중복할당을 허용하여 분할하고, 디스크에 단편(fragment)으로 저장하므로써 필요한 단편만을 액세스하여 디스크의 액세스 횟수를 줄이는 방법을 연구하였다. 본 연구에서는 속성의 중복할당을 허용하여 디스크의 액세스 횟수를 최소화시킬 수 있는 수직분할문제에 수리모형을 조회, 갱신트랙잭션을 모두 고려하여 0-1 정수계획법으로 개발하였다. 또한 모형에 대한 최적해법으로 분지한계법을 제안하였으며, 분지한계법으로 큰 문제를 푸는데는 많은 시간이 소요되므로 계산량을 줄일 수 있는 초기처리방법과 비용계산방법을 제안하였다. 속성의 중복을 허용하여 구한 해가 중복을 고려하지 않은 경우의 해보다 디스크 액세스횟수가 감소한 것으로 나타났으며, 갱신트랜？션의 수가 증가함에 따라 중복되는 속성의 수가 감소하는 결과를 나타내었다.

• 발명특허
• /
• 제30권6호통권348호
• /
• pp.36-39
• /
• 2005

복개되었던 청계천을 살리기 위한 서울시의 정책추진으로 청계고가가 철거되고, 그 위를 뒤덮었던 콘크리트 도로들이 사라지면서 청계천이 사람들의 눈앞에 모습을 드러냈다. 오래도록 도로 아래 묻혀있던 청계천은 그 복원을 계기로 많은 이들에게 생활하천이던 청계천의 옛 모습을 기억하게 했다. 삼삼오오 둘러앉아 빨래를 하거나 멱을 감는 아련한 추억으로, 혹은 빛바랜 사진으로 말이다. 추억 속 그 시절은 사람이 많이 살지 않고 빨래나 멱을 감는 것이 큰 하수가 아니었지만, 도시가 개발되고, 사람들이 많아지고, 생활하수가 늘어나면서 하수처리의 문제는 오늘날 도시계획 속에 포함될 만큼 중요한 문제가 되었다. 사람이 사는 곳이라면 어디든지 하수가 생기기 마련이다. 생활하수이건 산업하수이건 그로 인해 생겨나는 오염된 물, 오수인 하수는 불결하기 마련이다. 이 하수가 제대로 배수되지 않으면 전염병의 원인이 되기도 하고 생활 주변환경을 심각하게 오염시키는 결과를 초래하게 된다. 그렇기 때문에 하수는 신속하게 사람들이 살고 있는 환경 주변에서 배제되어져야 하며 하수도는 그 하수들을 처리하는 과정으로 하수도관과 종말처리장, 유수지 배수펌프장으로 구분된다. 이 하수를 처리하기 위해 하수관이 시가지 안의 도로 아래에 그물모양으로 어지럽게 깔려 있는데 도로 아래 매립되어 있기 때문에 견고한 시공이 필수적이다.

• Journal of the Korean Institute of Landscape Architecture
• /
• 제45권6호
• /
• pp.98-114
• /
• 2017

This study analyzed the commemorative landscapes of eight Holocaust concentration camp memorials(HCCM) of Germany and Poland from a landscape architecture point of view including historical landscape, places and remains, and monuments. A site survey was conducted at Dahau concentration camp memorial(CCM) and Bergen-Belsen CCM of Germany in September of 2015 and the Auschwitz-Birkenau extermination camp memorial(ECM), Majdanek ECM, Belzec ECM, Sobibor ECM, Treblinka ECM, Chelmno ECM of Poland in April of 2016. The results are as follows. First, the landscape of the concentration camp at Dahau CCM, Auschwitz ECM, and Majdanek ECM liberated by the Allied Forces was well conserved with the maintenance of camp facilities and the spatial structure of camps while monuments and memorials seized by sociopolitical argument were built with restriction. But Belzec ECM, Sobibor ECM, Treblinka ECM, and Chelmno ECM devastated and planted artificially to forest were overwhelmingly surrounded with natural landscape, and also, excavated relics and remains were preserved and the monuments were built at the place of memory. Second, gas chambers, crematoriums, guard posts, electric wire fences, railroads and ramps, barracks, and drainage ditches were considered to be typical facilities present in the camp structure and the gas chambers, crematoriums, human ashes, and mass graves demonstrated the horrible history of these camps and the railroad and ramp where Jewish prisoners arrived also had the strong sense of place. These remains were regarded as symbolic elements to create a memory of the tragedy and place. Third, commemoration of victims was applied as the basic concept and recalling the memory of the Holocaust was also considered very important content. Religious reconciliation and peace was represented at Dahau CCM and the Jewish identity was strongly expressed at Treblinka ECM and Belzec ECM representing the Jewish community and Judaism. Fourth, the monuments with semi-abstract styles and abstract sculptures represented the Holocaust symbolically and narratively and came into the conflict caused by the abstractness to the memorial landscape at Auschwitz-Birkenau ECM and Bergen-Belsen CCM. Fifth, remains for recalling the memory of tragedy and place and symbolic monuments to stand for public memory were juxtaposed at the same place and preserving on the authenticity of camp site had been conflicted with monumentalizing intentionally. Further study will required a concrete investigation of the monuments in the HCCM and an attempt to comparatively study the commemoration characteristics of memorials in Korea.

• Journal of the Korean Chemical Society
• /
• 제44권1호
• /
• pp.68-73
• /
• 2000

In this study, tlhe relationships of high school students' abilities to solve chemistry problems with cognitive variables (logical thinking ability, mental capacity. and learning strategy) and affective variables(self-efficacy, self-concept of ability, learning goal, and attitude toward science) were investigated. The proportion of variance due to the variables for algorithmic and conceptual problem solving ability was studied by a multiple regression analysis. The results indicated that, among the cognitive variables, the logical thinking ability significantly predicted the algorithmic problem solving ability, and the learning strategy was the best predictor of conceptual problem solving ability although not significant. Among the affective variables studied, the self-concept of alility was the significant predictor of both algorithmic and conceptual problem solving abilities. The seif-efficacy was significantly correlated with conceptual problem solving ability, but it had no predictive power.

• Journal of Educational Research in Mathematics
• /
• 제25권4호
• /
• pp.571-598
• /
• 2015

This study aimed to assess the spatial cognition strategies and roles taken by students in the process of solving spatial tasks. For the analysis, this study developed two spatial tests based on the mental rotation test, which were taken by 63 students in their final year in elementary schools. The results of this study showed that in terms of the method of approaching the tasks, students took the comprehensive approach and the partial approach. When solving the tasks, the students were shown to use the imagery thinking or analytic thinking method. In terms of perspective, the students rotated the object or change their perspectives. A comparison of the methods used by the students revealed that when approaching the tasks, the group of students who chose the partial approach had higher scores. In terms of solving the tasks the analytic thinking method, and in terms of perspective, changing perspectives were shown to be more effective. Such effective methods were used more frequently in discrimination tasks than in recognition tasks, and in more complicated items, than in less complicated items. In conclusion, the results of this study suggested that the partial, analytic approach and the change of perspectives are useful strategies in solving tasks which require high cognitive effort.

• Lingua Humanitatis
• /
• 제1권1호
• /
• pp.235-251
• /
• 2001

According to Chomskyan grammar, humans can generate and understand an unbounded number of grammatical sentences. Against the background of pure and idealized linguistic competence, this linguistic productivity is argued and understood. In actual utterances, however, there are many limitations of productivity but they are said to come from the general constraints on performances such as capacity of short term memory or attention. In this paper I discuss a problem raised against idealized productivity. I argue that linguistic productivity idealizes our linguistic competence too much. By separating idealized competence from the various constraints of performance, Chomskyan theorists can argue for unlimited productivity. However, the absolute distinction between grammar (pure competence) and parser (actual psychological processes) makes little sense when we explain the low acceptability(intelligibility) of center embedded sentences. Usually, the problem of center embedded sentence is explained in terms of memory shortage or other performance constraints. To explain the low acceptability, however, we need to assume specialized memory structure because the low acceptability occurs only with a specific type of syntactic pattern. 1 argue that this special memory structure should not be considered as a general performance constraint. It is a domain specific (specifically linguistic) constraints and an intrinsic part of human language processing. Recent development of Chomskyan grammar, i.e., minimalist approach seems to close the gap between pure competence and this type of specialized constraints. Chomsky's earlier approach of generative grammar focuses on end result of the generative derivation. However, economy principle (of minimalist approach) focuses on actual derivational processes. By having less mathematical or less idealized grammar, we can come closer to the actual computational processes that build syntactic structure of a sentence. In this way, we can have a more concrete picture of our linguistic competence, competence that is not detached from actual computational processes.

• Korean Journal of Culture and Social Issue
• /
• 제24권1호
• /
• pp.29-47
• /
• 2018

Do social situations have an impact on an individual's information processing and emotional experiences? Two studies were conducted to investigate relationships between self-reference effects, emotional experiences and social information processing. Study 1 examined whether biases favoring self-related stimuli could occur automatically. Participants had to judge whether sequential geometric shape-label pairs matched or mismatched. The results showed that self-related stimuli are more rapidly processed than friends/others-related stimuli. In Study 2, the participants had to recall items which were presented with different instructions (either chosen by a friend or by the computer). Here we explored whether the self-reference effect is reduced in a social learning condition. When comparing the social learning condition (seated in pairs) with the nonsocial learning condition (seated alone), the participants recalled more self-related words in the nonsocial learning condition than in the social learning condition. Importantly, the automatic self-reference effect disappeared in the social learning condition. More friends-related words were recalled in the social condition than self-related words. In addition, while tasting chocolates, the participants judged them to be more likeable in the social condition than in the nonsocial condition. These results implicated that social processing can be useful for reducing the automatic self-reference effects and shared experiences are perceived more intensely than unshared experiences.

• Korean Journal of Culture and Social Issue
• /
• 제16권2호
• /
• pp.179-195
• /
• 2010

Media reports of suicides has been found to increase suicide cases that were temporally and spacially proximal to the reports, but the psychological mechanisms, social learning, underlying the negative effects was not directly tested. The present study examined the cognitive processes of social learning that media reports of suicides, especially positive contents toward suicides, might change people's perception, memory, and attitudes toward suicides positively and subsequently increase subsequent suicide intentions and behaviors. Through an internet survey, 300 adults reported their perception, memory, and attitudes toward news reports of suicides, and rated whether the suicides were described positively or negatively in the reports. Finally they reported their suicide intentions and behaviors. The results revealed that people tended to remember more the contents of suicide reports suggested to increase copycat suicides. Also, people were found to have an ironic view to suicide reports of media that they acknowledged the dangers of suicides reports and approached the reports with curiosity. More importantly, the perception of the positive reward that suicides might achieved through suicides was related with positive attitudes toward suicides and behavioral intention to suicides. The present findings was discussed in the social learning understanding of copycat suicides and their implications for suicide-prevention strategies.